A Rededication to a Father
By Heidi Sproat
Armed with new technology and fairly accurate GPS coordinates, David steeled himself to the arduous task of relocating a plane crash site and a plaque he had placed in memory of his father which he had installed on a granite rock southwest of Independence Lake – 51 years ago.
At only eight months old, David Henderson, Jr., lost his Air Force pilot father, Captain David Howard Henderson, in a fierce Sierra November 13, 1955 storm. Stationed at Craig Air Force Base (AFB), in Selma, Alabama, the 34 year old father was flying from San Fernando Valley Airport in Van Nuys, California, headed for McClellan AFB, a flight that was suppose to be a one hour five minute training mission route. The aircraft number was 51-4339, a Lockheed T33A Shooting Star plane. High gusty winds with a tail wind up to 60 knots, precipitation and snow contributed to the violent plane crash about seven miles north of Donner Summit Radio Beacon, west of Independence Lake, and was completely destroyed. Wreckage was strewn for three quarters of a mile through heavy timber. The plane exploded and burned on final impact. According to the 159 page unclassified USAF accident report 551113, the aircraft went into an uncontrolled maneuver after shearing the left wing. Official documentation and personnel support statements attested to Henderson’s outstanding pilot qualifications, so what was the cause of the accident?
It is believed Captain Henderson experienced radio navigation issues caused by either the “grossly inadequate” (p. 39) and unreliability of his radio compass or a tuning error causing him to receive the Donner Summit beacon and not McClellan’s. Henderson was using Instrument Flight Rules (IFR) and adverse weather conditions contributed to the crash. On further investigation, it was learned that the frequences for McClellan AFB (395 Kilocycles kHz) and Summit (385 Kilocycles kHz) homer beacons were only a ten-digit difference! (pp. 40, 109-115). Additionally, the two beacons are only 60 nautical miles apart. But flying in the Donner Summit Beacon area, any signal was expected to be much stronger than the McClellan beacon (p. 39). An evaluation form by a colleague, USAF Captain C.W. Patterson, said that it was “possible that the pilot had tuned in the wrong radio frequency on the … radio compass and made descent on wrong radio facility.” (p. 147) Imagine flying solo in a fierce snowstorm with howling 60 knot winds, with primitive radio communications and trying to understand the difference between 385 and 395 with the radio display not located at eye level and instead located on the forward floor and obstructed by a control column. (p. 39) [Note: The Donner Summit Weather Station sat atop Signal Hill. On the roof was painted airway station 15. On one side of the roof “Donner” was painted and on the other, “SL-SF” so pilots knew in which direction was Salt Lake and in the other, San Francisco."
https://web.archive.org/web/20250218221438/http://www.donnersummithistoricalsociety.org/pages/exhibits/historicalfirsts.html .]
At only eight months old, David Henderson, Jr., lost his Air Force pilot father, Captain David Howard Henderson, in a fierce Sierra November 13, 1955 storm. Stationed at Craig Air Force Base (AFB), in Selma, Alabama, the 34 year old father was flying from San Fernando Valley Airport in Van Nuys, California, headed for McClellan AFB, a flight that was suppose to be a one hour five minute training mission route. The aircraft number was 51-4339, a Lockheed T33A Shooting Star plane. High gusty winds with a tail wind up to 60 knots, precipitation and snow contributed to the violent plane crash about seven miles north of Donner Summit Radio Beacon, west of Independence Lake, and was completely destroyed. Wreckage was strewn for three quarters of a mile through heavy timber. The plane exploded and burned on final impact. According to the 159 page unclassified USAF accident report 551113, the aircraft went into an uncontrolled maneuver after shearing the left wing. Official documentation and personnel support statements attested to Henderson’s outstanding pilot qualifications, so what was the cause of the accident?
It is believed Captain Henderson experienced radio navigation issues caused by either the “grossly inadequate” (p. 39) and unreliability of his radio compass or a tuning error causing him to receive the Donner Summit beacon and not McClellan’s. Henderson was using Instrument Flight Rules (IFR) and adverse weather conditions contributed to the crash. On further investigation, it was learned that the frequences for McClellan AFB (395 Kilocycles kHz) and Summit (385 Kilocycles kHz) homer beacons were only a ten-digit difference! (pp. 40, 109-115). Additionally, the two beacons are only 60 nautical miles apart. But flying in the Donner Summit Beacon area, any signal was expected to be much stronger than the McClellan beacon (p. 39). An evaluation form by a colleague, USAF Captain C.W. Patterson, said that it was “possible that the pilot had tuned in the wrong radio frequency on the … radio compass and made descent on wrong radio facility.” (p. 147) Imagine flying solo in a fierce snowstorm with howling 60 knot winds, with primitive radio communications and trying to understand the difference between 385 and 395 with the radio display not located at eye level and instead located on the forward floor and obstructed by a control column. (p. 39) [Note: The Donner Summit Weather Station sat atop Signal Hill. On the roof was painted airway station 15. On one side of the roof “Donner” was painted and on the other, “SL-SF” so pilots knew in which direction was Salt Lake and in the other, San Francisco."
https://web.archive.org/web/20250218221438/http://www.donnersummithistoricalsociety.org/pages/exhibits/historicalfirsts.html .]
In the 1950s, the apparent reason the Civil Aeronautics Administration (CAA) and the military assigned
385 kHz and 395 kHz so close together was the massive physical barrier of the Sierra Nevada mountain range. Without getting into too much technical detail, suffice it to say that the granitic terrain rising up to Donner Summit weakened groundwave signals. Because McClellan was located in the Sacramento valley, any pilot low enough in the Tahoe/Donner area would not have had their ADF (Automatic Direction Finder) pulled away by the more powerful McClellan military transmitter. Further, the Donner Summit Airway Station beacon was so designed to relay a signal down the canyon corridors to guide transcontinental mail and military flights safely through the treacherous Sierra Nevada “hump.”
The accident report concluded that the “primary cause of this accident cannot be determined since the wreckage has not been found. However, the members of the Accident Investigation Board believe that the most probable cause of this accident was a radio navigation error caused by the inadequacy of the radio navigation equipment installed in this model T-33 aircraft.” (p. 119). The final report also emphasizes that all pilots were subsequently “reinstructed to never start an instrument penetration unless they are positive of their position and to use all facilities available in the area for establishing their position.” (p. 128) ReSadly, the wreckage was still not even located until July 24, 1956, some eight months later. (p. 116) There are at least nine newspaper accounts about this aircraft accident. Only recently were we able to locate the Obituary from the Sedalia Democrat, August 12, 1956, p. 4. Nine months to the day of the aircraft crash, Captain Henderson was buried in Arlington National Cemetery.
385 kHz and 395 kHz so close together was the massive physical barrier of the Sierra Nevada mountain range. Without getting into too much technical detail, suffice it to say that the granitic terrain rising up to Donner Summit weakened groundwave signals. Because McClellan was located in the Sacramento valley, any pilot low enough in the Tahoe/Donner area would not have had their ADF (Automatic Direction Finder) pulled away by the more powerful McClellan military transmitter. Further, the Donner Summit Airway Station beacon was so designed to relay a signal down the canyon corridors to guide transcontinental mail and military flights safely through the treacherous Sierra Nevada “hump.”
The accident report concluded that the “primary cause of this accident cannot be determined since the wreckage has not been found. However, the members of the Accident Investigation Board believe that the most probable cause of this accident was a radio navigation error caused by the inadequacy of the radio navigation equipment installed in this model T-33 aircraft.” (p. 119). The final report also emphasizes that all pilots were subsequently “reinstructed to never start an instrument penetration unless they are positive of their position and to use all facilities available in the area for establishing their position.” (p. 128) ReSadly, the wreckage was still not even located until July 24, 1956, some eight months later. (p. 116) There are at least nine newspaper accounts about this aircraft accident. Only recently were we able to locate the Obituary from the Sedalia Democrat, August 12, 1956, p. 4. Nine months to the day of the aircraft crash, Captain Henderson was buried in Arlington National Cemetery.
We learned that by the late 1950s and 1960s, these close low/medium frequency (L/MF) assignments were phased out as aviation transitioned to VHF-based VOR navigation systems to avoid this very type of “frequency crowding.” [Note: VOR stands for VHF Omnidirectional Range, a ground-based radio navigation system used by pilots to determine their aircraft's position and stay on a precise course.]
After the McClellan Air Force Base searchers found the wreckage the following year, precisely reported July 25, 1956, and cleared the site, it wasn't until the summer of 1974 that David and his brother Richard spent weekends traipsing over the rugged terrain trying to locate the wreckage. Finally in September of that year it was located, and in July of 1975, Captain Henderson’s now fifty-five year old widow with all her children and one grandson hiked into the remote area and placed a memorial plaque on a granite rock in the crash site area.
After the McClellan Air Force Base searchers found the wreckage the following year, precisely reported July 25, 1956, and cleared the site, it wasn't until the summer of 1974 that David and his brother Richard spent weekends traipsing over the rugged terrain trying to locate the wreckage. Finally in September of that year it was located, and in July of 1975, Captain Henderson’s now fifty-five year old widow with all her children and one grandson hiked into the remote area and placed a memorial plaque on a granite rock in the crash site area.
What does all this have to do with the Truckee-Donner Historical Society (TDHS)? Fast forward to May 2026 when Captain David’s son – also David - contacted the Society in hopes we could provide some necessary assistance if he was to revisit the site one last time. David had already read other articles on our website about the March 1946 C-47 crash also near Independence Lake, also in winter, the follow up 2025 visit, and the two articles about Disney’s attempt to develop the Independence Lake area. Article 1; and article Part II.
Now 71 years old, the son David desperately wanted to revisit the area one last time in hopes of relocating the memorial plaque to his father set some 51 years ago. David had also contacted The Nature Conservancy’s Independence Lake Preserve and the Truckee Donner Land Trust attempting to get permission to access the site and to collect as much information as possible before he made his visit.
Now 71 years old, the son David desperately wanted to revisit the area one last time in hopes of relocating the memorial plaque to his father set some 51 years ago. David had also contacted The Nature Conservancy’s Independence Lake Preserve and the Truckee Donner Land Trust attempting to get permission to access the site and to collect as much information as possible before he made his visit.
This revisit occurred on Tuesday, August 25, 2026. David is the only remaining son of Captain Henderson. David, his younger sister and her husband were kindly boat shuttled from the east end of Independence Lake to the west end by the Nature Conservancy where they disembarked and started their ascent. Once one crosses the many marshy creek inlets on the west end, the trail rapidly turns into a demanding off-trail mountain ascent through heavy timber and steep, loose “granitic talus” (scree). Climbing would be from the lake level about 6,950 feet up to about the 7,600 foot mark where the crash site is, about 1 ½ - 2 miles UP.
Starting at the crack of dawn, David and family members took the boat ride to the west end of Independence Lake and started the rough trek up hoping to locate the crash site. After hiking for 6 hours, regrettably, the trio could NOT locate the site in the allotted time. Disappointing to say the least as the parties believed this would be their last attempt to visit the area.
I just couldn’t let this touching tribute to a deceased father go unnoticed. Trying to revisit the site was a commendable salute to a father whose wife and children lost him way too young.
David was kind enough to share some photos from the original dedication in 1975 which are reproduced below. Also included are some excerpts from the official USAF accident report.
I dedicate this article to the Henderson family’s perseverance, commitment, and unwavering tribute to honor their father.
NOTES: The Henderson obituary is available at Sedalia Democrat, August 12, 1956, p. 4. Numbers in parentheses refer to the page numbers from the Official Declassified SUPPLEMENTAL Report of AF Aircraft Accident.
Starting at the crack of dawn, David and family members took the boat ride to the west end of Independence Lake and started the rough trek up hoping to locate the crash site. After hiking for 6 hours, regrettably, the trio could NOT locate the site in the allotted time. Disappointing to say the least as the parties believed this would be their last attempt to visit the area.
I just couldn’t let this touching tribute to a deceased father go unnoticed. Trying to revisit the site was a commendable salute to a father whose wife and children lost him way too young.
David was kind enough to share some photos from the original dedication in 1975 which are reproduced below. Also included are some excerpts from the official USAF accident report.
I dedicate this article to the Henderson family’s perseverance, commitment, and unwavering tribute to honor their father.
NOTES: The Henderson obituary is available at Sedalia Democrat, August 12, 1956, p. 4. Numbers in parentheses refer to the page numbers from the Official Declassified SUPPLEMENTAL Report of AF Aircraft Accident.
HCS 9/4/2026
Henderson’s plane radio call sign 14339 (p. 56)
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apparent speed 420 knots (p. 59)
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Aircraft clock stopped at 13:56 (p. 106)
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Hit 18” diameter treetop 40 feet up (pp. 29, 91). Notation states "Tree that sheared left wing, severe damage commenced here."
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Henderson’s salvaged gyro set an inbound heading of 160 degrees to McClellan Air Force Base (p. 61)
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Photo taken the day of the revisit hike, August 25, 2026, Independence Lake in the background.
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